Reply #124: Small devil's advocate point:

[Ken Burch]

It's possible an employee could have already made copies of confidential and/or sensitive files and have them at home, giving that employee the chance to gain vengeance by selling the files to some other person or entity, thus gaining both financial reward and vengeance.

The use of muscle could actually provoke valueable employees to prepare such schemes in advance-thus making the "only responsible way" to remove an employee that you outline above utterly useless in security terms.

Something to consider.